Chapter 5
Basic Signal Leader Information
This chapter contains six sections. Each
section provides guidance on performing a
different task or area of importance
common to signal leaders.
Obtaining LOS between two stations is
essential when forming a multichannel
radio link. For most systems, the LOS
planning range is about 40 kilometers,
due to the earth's curvature.
LOS
analysis may be done by automated
means,
usually
by
the
signal
brigade's/battalion's S3. See Figure 5-1.
SECTION I - PROFILING RADIO LINKS
5-1. To perform a manual radio LOS analysis, obtain
the following materials:
 Grid coordinates of both stations.
 Path profile paper, 4/3 earth radius (if possible).
 Map sheet containing both stations.
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 GTA 5-2-12 protractor and coordinate scale.
5-2. Perform the following steps:
 On the map sheet, place a dot at each proposed
site location and circle it for ease of finding it
later.
 Draw a line from point A to point B and
determine the distance between the two.
 If the distance is greater than 48 kilometers (40
kilometers for MSE), the points exceed maximum
planning range and the transmissions may be too
weak to receive.
A relay may be needed;
however, its use is undesirable and should be
used as a last resort so that unnecessary assets
are not tied up in one radio link.
 Determine the elevation in meters of the
originating and destination stations. Plot them
the proper distance apart on the profile paper.
Remember to add the antenna heights.
 Divide the distance between the stations into 1
kilometer increments.
 Determine the highest elevation in meters at 1
kilometer increments. Plot these on the profile
chart.
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 Connect the points to establish a graphic picture
of the terrain along the path between the two
stations.
 Draw a straight line between the antenna
stations. This line represents the multichannel
radio transmission path.
 If the transmission path does not clear the
terrain, LOS is not possible. Another terminal
site or a relay site should be chosen. Leaders at
company, platoon and team level should
manually profile radio shots as soon as possible.
TC 24-21 explains LOS manual profiling methods
in detail.
Section II - Convoy Operations
Figure 5-1. Sample LOS study.
5-3
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Section II - Conducting Convoy Operations
CONVOY ORGANIZATION
5-3. A convoy is a group of vehicles organized under a
single commander for movement. It consists of—
 The march column. All vehicles involved in a
single move along the same route.
 The serial. Subdivision of vehicles moving from
the same area along the same route.
 The march unit. Subdivision of a serial.
5-4. The march unit consists of march unit elements.
These are—
 Advance/Trail Elements. These are not a part
of the main march unit. They are detailed to
perform special duties such as quartering and
reconnaissance. Some tactical situations may
require advance, flank, or rear guards. Heavily
traveled routes and busy intersections may
require guides, escorts, and patrols.
 Lead Element. First vehicle in the column.
Contains the pace setter/navigator who ensures
proper route and checks for changes to orders at
predetermined points.
 Main Body. Column of vehicles comprising the
bulk of the convoy.
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 Trail Element. Last vehicle in the column. The
trail
element
contains
a
trail
officer/noncommissioned
officer
(NCO)
responsible for maintenance and medical
support.
CONVOY PLANNING FACTORS
INTERVAL
5-5. Distance between vehicles depends on many
variables.
 Urban areas 50 meters.
 Rural areas
150 meters.
 Expressways 200 meters.
CONVOY SPEED
5-6. Convoy speed depends on road conditions, traffic
conditions, and the speed of the slowest vehicle.
 Cities/built up areas
24 Km/h (15 MPH).
 Two lane roads
40 Km/h (25 MPH).
 Limited access expressways 66 Km/h (40 MPH).
 Blackout Drive
8 Km/h ( 5 MPH).
CONVOY SECURITY.
5-7. Military police (MP) units may provide convoy
security on a continuous or intermittent basis. MP
support depends on the threat in the area of operations.
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If MP units do not provide support, the convoy
commander must plan for security. This includes—
 Noise and light discipline.
 Front, flank, and rear security.
 Security during halts.
 Air cover.
 Fire support.
 Communications.
 Checkpoints.
5-8. Start and Release Points.
 Start point (SP). This is where all elements of
a column come under the control of the convoy
commander. The SP must be a place along the
route easily recognized on both maps and ground.
 Release point (RP). This is where elements of
the column are released to their individual
control. The RP, like the SP, must be a place
along the route easily recognized on both maps
and ground. The RP should have multiple exits
to prevent congestion.
5-9. Halts.
 Time. Plan 10 minute rest halts every 2 hours.
Plan longer halts for dining, refueling, and
bivouacking.
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 Location. Choose halt locations in advance and
identify good characteristics for dispersion and
concealment according to operational conditions.
5-10. Personnel Duties During a Halt.
 Officers and NCOs check the welfare of the
soldiers, the security of loads, vehicular
performance, fuel levels, and the performance of
maintenance.
 Control personnel should inspect and give
instructions to ensure the column begins with
minimal confusion.
 Drivers should inspect their vehicles and loads.
 Drivers should perform preventive maintenance
checks and services (PMCS)/during operations
check.
 Assistant drivers must stay alert and be able to
fill in for the driver when needed.
5-11. Additional planning factors.
 Route reconnaissance.
 Tactical situation.
 Strip map preparation and distribution.
 Obtaining convoy clearance.
 Contacts
along
route
for
medical,
decontamination, and vehicular support.
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 Status of trained drivers.
 Number of vehicles involved.
 Types of loads.
 Traffic conditions.
 Communications for convoy control.
CONVOY COMMANDER'S BRIEF
5-12. Before departing, the convoy commander should
issue strip maps and conduct a briefing for all convoy
members. Figure 5-2 shows a typical strip map.
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Figure 5-2. Typical strip map.
5-13. Recommended briefing subjects that should be
covered are shown in the outline below.
 Situation:
 Friendly forces.
 Support units.
 Enemy situation.
5-14. Mission:
 Origin.
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 Route.
 Destination.
5-15. Execution:
 General organization of the convoy.
 Time schedule.
 Night operations.
 Risk assessment.
5-16. Route:
 Convoy speed.
 Catch-up speed.
 Control personnel.
 Security forces commander.
 Fire support commander.
 Medical evacuation support and safety.
 Hazards of route and weather conditions.
 Defensive driving principles.
 Interval between vehicles.
 Decontamination
routes.
points
and
5-17. Emergency Measures:
 Breakdown/accident procedures.
 Use of highway warning kits.
5-10
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 Separation from convoy procedures.
 Ambush (actions taken).
 Contingency plans.
ADMINISTRATION AND LOGISTICS:
 Billeting arrangements.
 Messing arrangements.
 Refueling of vehicles.
 Supply support, Class I-IX.
COMMAND AND SIGNAL:
 Primary and backup radio frequencies.
 Location and call sign of convoy commander.
 Location and call sign of assistant convoy
commander.
 Location and call sign of medical support
personnel.
NOTE: Appendix O of FM 55-30 provides a sample
convoy commander's checklist.
Section III - Signal Site Selection/Set Up
5-18. Select
sites
and
routes
using
ground
reconnaissance when possible. Use an aerial or map
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reconnaissance when a ground reconnaissance is not
possible.
SITE RECONNAISSANCE
5-19. As soon as the team knows where it will deploy, it
conducts a thorough reconnaissance. For an NC, this
usually includes the platoon leader, platoon sergeants,
LOS supervisor, security and NBC team. The NC's
reconnaissance must be extremely detailed as site
selection and layout are critical to network success. NC
reconnaissance is considered complete when the platoon
leader can fill out the NC diagram showing- Antenna and LOS(V3) placements.
 RAU locations.
 NC switch/NMF locations.
 Hasty defensive sites and security plans.
5-20. The LOS has first priority of placement, the local
RAU second, and the NC switch/NMF last. The platoon
leader also determines if the database needs modifying
and back briefs his command on his site layout and
initial security procedures.
SITE SELECTION.
 Select the site that best meets the following
criteria:
 Site should be level and allow sufficient space for
tactical dispersion of communications equipment
in addition to subscriber space requirements.
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 Site must have a clear LOS path for radio
systems, must be free of obstacles that prevent
transmissions, and away from interference sources
such as power lines, generators, or other
antennas.
 Site should be accessible in all weather conditions.
 Site should provide overhead cover and
concealment with adequate dispersion of assets,
be defendable, have more than one exit, and not
attract enemy attention.
 Site should have a helicopter-landing zone for
emergencies or supplies.
SITE PLANNING
5-21. Once a site has been chosen, do the following in
accordance with the unit SOP:
 Estimate equipment placement, subscriber
location, initial observation post, sleeping, dining
and latrine areas, dismount points, parking
space, and restricted areas.
 Draw a site sketch including the above items.
 Coordinating for the site with higher
headquarters, subscriber units, and other
appropriate elements.
 Prepare strip map with primary and alternate
routes to the site.
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 Distribute strip maps to appropriate personnel.
SITE SET-UP
5-22. The following are points to consider when setting
up a signal site:
 Maintain a tactical configuration and position
the operations van in a central location. This
allows easy control of the site.
 Position the radio vans on the edge of the site in
the direction they will be shooting. This allows
the antennas to have the most direct shot
without crossing anything on the site.
Generators and power lines must be kept as far
away from the antennas as possible.
 Maintain switches in a central location to allow
ease of installing cables to multichannel and
other radio vans.
 Allow easy access to generators.
 Back vehicles into designated parking areas to
allow for rapid displacement.
Section IV - Signal Site Security
DISCIPLINES
TYPES OF SIGNAL SITES
5-23. Signal sites must be able to defend against
sabotage, ground forces, and airborne/air assault forces
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with little or no outside help. They must also be
prepared to survive enemy air, artillery, and NBC
attack.
5-24. There are different signal sites and different
considerations must be made when planning a site
defense for each. Current threat status/situation is an
important factor when planning and committing assets
and personnel to defend a site. Use mission, enemy,
terrain, troops and time (METT-T) considerations and
order priorities accordingly.
REMOTE SITES
5-25. These are small teams located in isolated
positions, usually for relay or retransmission purposes.
They cannot hope to defeat a large enemy force. Teams
should try to remain concealed and report enemy
activity to higher headquarters.
Conduct risk
assessment for remoted sites to determine the
probability of mission success. Leaders must carefully
track specific threats and move quickly when in danger.
COLLOCATED SITES
5-26. These are usually teams that deploy to support a
unit CP, such as an extension node. Usually, the team
members are responsible for a portion of the perimeter
defense. Careful coordination must be done with the
collocating units. All defense matters for the site
should be the responsibility of one central authority.
Node Sites
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5-27. This is usually a platoon-sized signal unit that
may or may not collocate with another unit. Based on
the +6 enemy threat level, the signal site commander
must plan a site defense and coordinate with nearby
units for mutual support.
SITE DEFENSE TASKS
5-28. The following list provides guidelines for planning
a site defense and should be prioritized according to the
mission.
 Set up a dismount point and a blackout drive
line.
 Park vans at least 50 meters apart or as dictated
by the tactical situation and/or environment to
allow minimum damage from indirect fire.
 Camouflage tents, vehicles, and equipment.
 Set up defensive positions with interlocking fields
of fire.
 Ensure aiming stakes are in place and place
antipersonnel mines along probable foot
approaches.
 Set up personal defensive positions within the
site.
 Establish overhead cover.
 Establish a site defense command center.
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 Establish listening points outside earshot of
generators.
 Establish a roving guard force to cover the
perimeter and check on fighting positions.
 Establish external patrols to periodically sweep
the immediate area outside the perimeter.
 Position and over-watch obstacles, mines, and
trip wires.
 Position light antitank weapons (AT-4) along
vehicle approach routes.
 Establish perimeter control.
 Ensure
communications
exist
to
observation/listening posts, dismount points,
fighting positions, and casualty evacuation
points.
 Establish an additional line between collocating
units and the signal command center.
 Set up NBC monitoring equipment.
 Establish rally points and reactionary force plan.
 Coordinate a call for fire plan.
 Inventory sensitive items often to provide an
accurate battle status.
 Plan for medical support and evacuation.
 Set up ammunition resupply points.
5-17
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 Set up a viable sleep plan that integrates into the
work/defense plan.
 Control weapons employment and ensure each
soldier has adequate ammunition (with
magazines).
 Rehearse your plan according to the standards
outlined in the appropriate Army Training and
Evaluation
Programs
(ARTEPs),
soldiers
manuals, and/or SOPs. (See Appendix C.)
5-29. Figure 5-3 gives a typical signal site defense
diagram.
5-18
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Figure 5-3. Signal site defense diagram.
5-30. The environment can take a severe toll on
communications. This section addresses a few specific
5-19
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problems involved in six environments: cold weather,
desert, jungle, mountain, urban, and nuclear.
NOTE: The operator must perform PMCS to
maintain all equipment in an operational status.
COLD WEATHER OPERATIONS
5-31. Soldiers must be trained on cold weather safety.
Extra precautions must be taken with heaters and open
fires. Carbon monoxide poisoning is a constant danger.
Snow and ice build-up on tents and vehicle canvas can
cause tearing.
GENERATORS AND VEHICLES
5-32. Grounding is difficult in frozen earth. Gloves
must be worn when handling all metal objects. If
possible, use existing underground pipes or above
ground structures to get an adequate ground.
Antifreeze and lightweight oil must be used for all
vehicles during cold weather operations. Liquid cooled
generators also need antifreeze.
Maintenance
personnel must check antifreeze levels often. Water
may appear in fuel and fuel lines.
Do not use
contaminated fuel. The fuel must be drained from the
vehicle and new fuel added before operating the vehicle.
Keep dry batteries warm and charge wet-cell batteries.
Vehicles must be started at least once a day and
operated for 10 minutes at a high revolutions per
minute (RPM) to charge the battery. Keep tire chains
tight to avoid damage to vehicles.
5-20
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RADIOS
5-33. Water vapor from the breath can freeze and make
a microphone useless. Use de-icing shields to prevent
this. Ice on antennas can cause damage and make it
hard to extend or lower the antenna. Ice can be melted
from the mast using a hose attached to the exhaust pipe
of a vehicle. Direct the hot air on the ice until it melts.
WIRE
5-34. Condensation and ice on connectors make
connecting the cables difficult and can degrade the
signal path. Care must be taken to keep connectors
dry. Extreme care must be taken in handling cables at
low temperatures. When the rubber jackets become
hard, the cables must be protected from stretching and
bending to prevent short circuits caused by breaks in
the covering. If cables are to be bent, they must first be
warmed.
DESERT OPERATIONS
5-35. Two of the biggest problems involved in desert
operations are dust and extreme heat. Dust and sand
particles damage equipment. The heat can take its toll
on generators, wire, communications equipment, and
personnel.
GENERATORS AND VEHICLES
5-36. Grounding equipment is difficult and can be
accomplished by burying grounding plates in the sand
5-21
FM 11-43______________________________________
and frequently pouring salt solutions on them. Special
attention must be taken to ensure air filters are cleaned
daily to prevent equipment damage.
RADIOS
5-37. Keep all radios cool and clean. Keep them in a
shaded or ventilated area whenever possible. Cover hot
radios with a damp towel without blocking the air
vents. Evaporation will cool the radio. After dark,
rapid temperature drops can cause heat inversion that
can disrupt radio communications until the atmosphere
stabilizes. Desert terrain can cause excessive signal
attenuation making planning ranges shorter.
WIRE
5-38. Bury wire and cables deep in soft sand, if
possible. This prevents damage to the cable insulation.
See FM 90-3 for more information on desert
operations.
JUNGLE OPERATIONS
5-39. During jungle operations, movement and
visibility are reduced by terrain and heavy foliage. This
same terrain and foliage provides adequate cover and
concealment.
Humidity and heat can cause
condensation. Microphones, wires, cables, and gauges
are especially susceptible to moisture and fungus.
5-22
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Battery life is shortened.
If air conditioning is
available, it is very effective against high humidity.
RADIOS
5-40. The range of radio communications is reduced.
Jungle growth and terrain that absorb transmissions
limit VHF and UHF radios. HF radios are more
effective. Airborne radio retransmission's are used to
overcome dense vegetation.
WIRE
5-41. Dense vegetation and difficult terrain limit using
wire in jungle operations. Aerial wire installation can
be used as an alternate dispensing method due to
mobility restrictions in jungle terrain.
See FM 90-5 for more information on jungle operations.
MOUNTAIN OPERATIONS
5-42. Mobility is difficult in mountainous terrain, and it
can be difficult to find a level area for a communications
site.
GENERATORS AND VEHICLES
5-43. Generators and communications assemblages
need level ground to operate properly. It is difficult to
drive ground rods and guy wire stakes into rocky,
mountainous terrain. The rocky soil provides poor
grounds, however, adding salt solutions will improve
the electrical flow.
5-23
FM 11-43______________________________________
RADIOS
5-44.When operating in mountainous terrain, additional
retransmission assets will be needed. LOS paths are
much more difficult to gain. Use of relays improves
communications. Positioning antennas is crucial in
mountainous terrain because moving an antenna even a
small distance can drastically affect reception.
See FM 90-6 for more information on mountain
operations.
URBAN OPERATIONS
5-45. Seizure of cities and towns consume enormous
resources, degrade the momentum of offensive
operations, restrict maneuver, and are time-consuming.
RADIOS
5-46. Large buildings and electrical interference
greatly hamper LOS communications.
Using
retransmission helps to alleviate the problem. Aerial
retransmission is the most effective. If this is not
available, install antennas as high as possible. Avoid
using church steeples and other obvious places. It is
better to select a common type of building and install
the antenna.
Consider the background before
camouflaging antennas. Remember to remote radios to
separate the operators from the equipment. Position
retransmission stations near intersections to provide
better coverage.
5-24
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MULTICHANNEL RADIO
5-47. The effectiveness of multichannel radio is reduced
in an urban area because the radios require LOS. LOS
between units is nearly impossible in built-up areas.
Install multichannel radio systems only after the city is
relatively secure. Use an SHF radio shot to bring the
circuits into the supported headquarters.
TELEPHONE AND WIRE
5-48. The prompt seizure of the city and existing
communications facilities are very important. Notify
parent headquarters of controlled telephone numbers.
Public or private telephones coupled with stationing
messengers at the phones can provide excellent
emergency communications. Initially, telephone and
wire lines have limited use. Installation in sewer
systems, subway tunnels, or through intact buildings
provides increased protection for the wire. Use aerial or
overhead construction when installing wire along city
streets.
VISUAL SIGNALS
5-49. Pyrotechnics, smoke, and marking panels are
means of communications in the city.
NUCLEAR ENVIRONMENT
5-50. A nuclear environment is very damaging to
sensitive signal equipment. Leaders must know how to
protect vital assets for future use.
5-25
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ELECTROMAGNETIC PULSE (EMP)
5-51. The radiation from a nuclear burst produces
EMP. Gamma rays radiate outward from the burst and
strip electrons from the atoms in the air. This creates a
virtual wall of fast-moving electrons as the radiation
sweeps outward in an expanding wave. This process
creates a region of high voltage and strong interference.
SUSCEPTIBILITY
5-52. Signal equipment is very susceptible to EMP.
Normally, the smaller the individual component, the
more susceptible it is to electronic attack (EA).
EMP PROTECTIVE MEASURES
5-53. All equipment not required in primary systems
should remain disconnected and stored within a sealed
shelter or other shielded enclosure for protection from
the EA. This measure reduces the likelihood of all
equipment being simultaneously damaged by EMP and
provides for backup components to reinstall affected
systems.
WIRE AND CABLE
5-54. Wire and cable should be shielded and properly
grounded. The cable length must be kept as short as
possible. Shields on all cables connect to the grounding
systems where provided.
5-26
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RADIOS
5-55. Antennas should be disconnected from radio sets
when not in use.
Reduce operational nets to a
minimum. Most tactical radios with fully closed metal
cases will provide adequate EMP protection if all
external connectors have been removed. Placing items
in vehicles, vans, and underground shelters provide
effective protection.
SCIPLINES
Section VI - Power Generation Sources
BATTERIES
5-56. Signal equipment can use two types of batteries:
 Wet-cell batteries. These contain electrolytes
and normally provide greater amperage than dry
cell batteries for tasks like starting vehicles.
They require special attention to maximize their
life span.
 Dry-cell batteries. These do not need water or
acid. They can power smaller equipment such as
radios, flashlights, and SB-22 switchboards.
They can be ordered through the supply system
and kept on-hand until needed. Dry cell batteries
should be refrigerated to increase their life span
and should be removed from equipment when not
in use.
5-27
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5-57. It is crucial to maintain an adequate supply of
batteries for the unit. Use the following guidelines to
develop an SOP:
 Determine the unit's battery needs. Refer to the
property book to find equipment that uses
batteries.
Look in the equipment training
manuals to determine the type and number of
batteries each item takes and how long the
batteries will last.
 Determine the unit's battery usage and needed
stockage level. Use Supply Bulletin 11-6 to
obtain battery stock numbers, compute their
storage life, and handling/ disposal requirements.
 Ensure PLL's requisition required stock.
 Make a chart to keep track of the information.
5-58. Table 5-1 shows an example of the chart.
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Table 5-1. Sample portion of unit battery stockage
chart.
5-29
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COMMERCIAL POWER
5-59. This power is normally very reliable. However, in
the event of power failure backup generators and
vehicle DC power systems are vital alternatives. As a
fail-safe measure, backup power cables should be run to
the tactical generators.
ENGINE-DRIVEN GENERATOR UNITS
5-60. Tactical generators can produce either AC or DC.
DC generators can have output capacities from 0.4 to
15.9 kilowatts.
AC generators can have output
capacities from 0.3 to 1000 kilowatts.
5-61.Table 5-2 gives the approximate fuel consumption
rates of various generators. When operating at medium
to high temperature (50 to 100 F), a generator will
consume oil at one quart per eight hours of operation.
Table 5-2. Fuel consumption rates.
5-30
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Generator Pre-Start Up Checklist
5-62. Use the following checklist when employing
generators for power:
 Are TMs and PMCS lists available?
 Is the generator located on a flat surface, not
more than 15 from level?
 Are brakes set and wheels blocked securely to
prevent any movement of the trailer?
 Are all exhaust pipes and air intake filters free of
obstructions?
 Is grounding rod driven at no less than a 45
angle into the ground?
 Are ground straps securely connected?
 Does the engine have any loose or missing
wiring? Any oil or fuel leaks? Are air and fuel
filters clean?
 How often is the oil changed or checked?
 Have fuel containers been placed at least 50 feet
from equipment and a fire point set up?
 Are backup generators completely installed and
ready for use?
 Is the safety leg on the trailer being used?
 Are drip pans present and being used?
5-31